Process for the manufacture of a shaft bottom

Abstract

The invention relates to a method for producing a concrete shaft bottom which comprises a drain having a defined shape. According to said method, concrete is introduced into a bottom mold ( 1 ) that comprises a mold jacket ( 2 ) and a mold bottom ( 3 ). On said mold bottom ( 3 ), a molded body ( 8 ) forming the negative shape of the drain is disposed to configure the drain. The aim of the invention is to allow for the inexpensive and mechanized production of a shaft bottom having an individual drain. For this purpose, the molded body ( 8 ) is configured from at least one molded piece ( 9 ) that is fixed on the bottom mold ( 1 ), especially on the mold bottom ( 3 ). The molded piece ( 9 ) is adapted to the dimensions of the defined shape of the drain and is removed from the shaft bottom once or while the formwork is dismantled from the shaft bottom.

1. A process for manufacturing a shaft bottom part made of concrete and having an individual chute of a predetermined shape, wherein said process comprises the steps of:
 providing a plurality of prefabricated moulded pieces ( 9 ,  14 ) having a linear longitudinal extension and a plurality of prefabricated moulded pieces ( 10 ,  15 ) having an arc-shaped longitudinal extension; 
 selecting two or more moulded pieces ( 9 ,  10 ,  14 ,  15 ) out of said plurality of prefabricated moulded pieces ( 9 ,  10 ,  14 ,  15 ); 
 cutting and trimming the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) to adapt the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) to the predetermined shape of the chute,
 wherein cutting the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) comprises cutting the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) to a required length according to the predetermined shape of the chute and trimming the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) comprises trimming the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) in height according to the predetermined shape of the chute and/or trimming the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) at the face side of the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) for fitting together according to the predetermined shape of the chute; 
 
 assembling the selected moulded pieces ( 9 ,  10 ,  14 ,  15 ) for forming a moulded body ( 8 ) according to the individual chute geometry, said moulded body ( 8 ,  18 ) forming the negative mould of the chute; 
 inserting the moulded body ( 8 ,  18 ) into a bottom mould ( 1 ) comprising a mould bottom ( 3 ) and a mantle ( 2 ); 
 filling a mixture of concrete into the bottom mould ( 1 ); and 
 removing the moulded body ( 8 ,  18 ) from the shaft bottom after or simultaneously with stripping the formwork from the shaft bottom. 
 
     
     
       2. A process according to  claim 1 , characterized in that the moulded body ( 8 ) is formed from two or several differently shaped moulded pieces ( 9 ,  10 ,  14 ,  15 ) which are kept in stock. 
     
     
       3. A process according to  claim 1 , characterized in that the moulded piece or the moulded pieces ( 9 ,  10 ,  14 ,  15 ), respectively, is/are produced from a foamed material, a rigid-foamed synthetic material, a thermoplastic foamed material, or a synthetic material. 
     
     
       4. A process according to  claim 1 , characterized in that the moulded body ( 8 ) initially has a size which exceeds the floor area of the mould bottom ( 3 ) and, after being mounted to the mould bottom ( 3 ), is adjusted to the circumference of the mould bottom ( 3 ), with the mould bottom ( 3 ) being separated from the mantle ( 2 ) during this procedure. 
     
     
       5. A process according to  claim 1 , characterized in that a height adjustment corresponding to the depth and/or the gradient of the predetermined shape of the chute is performed on the moulded pieces ( 9 ,  10 ,  14 ,  15 ). 
     
     
       6. A process according to  claim 1 , characterized in that, in each case, one recess body ( 11 ) bridging over the radial distance between the mantle ( 2 ) and the mould bottom ( 3 ) is attached to the ends of the moulded body ( 8 ). 
     
     
       7. A process according to  claim 6 , characterized in that the recess bodies ( 11 ) are also formed from a foamed material. 
     
     
       8. A process according to  claim 7 , characterized in that the recess bodies ( 11 ) are adjusted, on the end side, to the gradient of the chute. 
     
     
       9. A process according to  claim 6 , characterized in that the recess bodies ( 11 ) are furnished, on the outside, with a seal ( 24 ) extending around the circumference prior to the introduction of concrete. 
     
     
       10. A process according to  claim 1 , characterized in that the moulded body ( 8 ) is provided with a separation aid ( 29 ,  30 ) prior to the introduction of the concrete. 
     
     
       11. A process according to  claim 10 , characterized in that the separation aid is formed by at least one film placed around the moulded body ( 8 ) and/or at least one band ( 30 ) placed around the moulded body ( 8 ), which band ( 30 ) is preferably provided in a recess of a moulded piece ( 9 ,  10 ,  14 ,  15 ) forming the moulded body ( 8 ). 
     
     
       12. A process according to  claim 10 , characterized in that the separation aid is formed by at least one resistance wire ( 29 ) provided in the moulded body ( 8 ). 
     
     
       13. A process according to  claim 1 , characterized in that the removal of the moulded body ( 8 ) after the formwork has been stripped from the shaft bottom is accomplished in that a wedge-shaped piece ( 28 ) is cut out of the moulded body ( 8 ), whereupon the remaining moulded body parts are folded up and easily lifted out of the chute, whereby the contact with the concrete is released. 
     
     
       14. A process according to  claim 1 , characterized in that the plurality of prefabricated moulded pieces are selected from the group consisting of prefabricated moulded pieces ( 9 ,  14 ) having a linear longitudinal extension and prefabricated moulded pieces ( 10 ,  15 ) having an arc-shaped longitudinal extension.